Industrial and paper-makers&#39; felts



: July11,1939. RHWAL H' 2,165,772

INDUSTRIAL AND PAPER-MAKERS FEL'I'S Filed May 4, 19:57 2 Sheets-Sheet 1 1 11 0617 56:35 PM WM 11 W (Zr/601 7163 July 11, 1939. P. H. WALSH Er AL 2,165,772

INDUSTRIAL AND PAPERMAKERS FEL'I'S Filed May 4, 1957 2 Sheets-Sheet 2 Inventors Patented July 11,1939

UNITED STATES INDUSTRIAL AND PAPER-MAKERS FELTS Patrick H. Walsh, Boston, Mass, and Percival T.

Gates, Montclair, N. J., assignors to Drycor Felt Company, Belleville, N. J., a corporation of New Jersey Application May 4, 1927, Serial'No. 140,652

1 Claim. (Cl. 23

Our present invention is a novel and improved construction of needled fabrics and method of making same, and is directed particularly to improve and perfect felts for use in paper manufacture and industrial lines.

In carrying out our invention we prefer to utilize the improved methods and machines for the manufacture of needled articles, such for example as illustrated in the prior Ur S. Patents No. 1,620,307, dated March 8, 1929, No. 1,743,068, dated Jan. 7, 1930, on Process of making textile fabrics; and No. 1,745,739, dated Fcb. 14, 1930, and No. 1,853,961, dated April 12,- 1932, on Needling apparatus; improving and modifying the fabric structure as will be hereinafter explained, and also building our improved article under suitable tension, all for the special purpose of producing an industrial felt and felts intended. for paper-making machines. a

The requirements foigpaper-makers felts, for example, are extremely severe, the felt being in the form of a belt which will receive, transport, and remove water from the pulp material, permitting the water and moisture to drain from such pulp while being transported, and with a smooth finished surface which will tend to elimi- Hate wrinkles, inequalities, or undesirable markings on the resultant paper product.

Furthermore, considerable difiiculty has been experienced heretofore in providing a belt which will be wear-resistant to the extremely severe requirements Where asbestos -or cement shingles, or the like, are being formed, the filtering action quickly filling the usual felt material with the dirt, cement, or the like, carried off by the water as it filters thru the belt and filling up the same, as well as wearing the belt out on the suction boxes and rollers over which it has passed.

Thus it will be appreciated that extremely severe service is required from articles of this sort, from the one extreme'of making soft, thin face tissues, such as cleansing tissue, paper towels, or the like, writing and bond paper,- .up to the heavier articlessuch as cement and asbestos shingles and the like industrial articles.

In carrying out our invention we practically eliminate the prior difficulties heretofore experienced, and have devised an extremely efficient, War-resistantand effective paper-makers and industrial felt which will insure constant drainage, minimize filling and clogging of the felt, and insure easy cleaning of the same, thus maintaining the porosity of the felt in satisfactory condition during use, and which will alsopulp and eliminate objectionable markings on the product.

It is a further feature of our present discovery to provide an extremely strong, wear-resistant structure with a special base fabric, preferably built under. tension. was to permit tensioning of the belt in use without distorting the fabric Rossuao AUG 2 1941 and with special surfacing of the fabric, and all i by the simple, efficient, and economical needling processes of said prior patents, and with great speed in operation.

Further improvements, novel combinations, and advantages will be hereinafter more fully pointed out and claimed, including our novel fabric with ply strands for the warp, and cable twisted strands for the filling.

Referring to the drawings illustrating a pre-:

ferred embodiment of our present invention,

Fig, 1 illustrates in diagrammatic form a.frag- V mentary step in the process of manufacturing cur improved felts, showing a schematic method ofneedling the layers to the base fabric, or fabrics, under tension utilizing a needling machine of said prior Patent No. 1,745,739, or the like;

Fig. 2 is an enlarged cross-sectional view illustrating a special type of needle which we have devised, and, preferably, employ during the needling operation;

Fig. 3 is a fragmentary cross-sectional view illustrating our improved fabric with a plurality of base members and a plurality of needlecl layers of different strength and texture;

Fig. 4 is a fragmentary cross-sectional view illustrating a preferred form of base fabric as woven for our particular industrialfelt construction and for needling under tension;

Fig. 5 is a fragmentary view of. our improved felt with a plurality of layers needled to a single base fabric;

Fig. 6 illustrates the same. in detailand crossrality of. fleece layers, preferably of wool, and

with a plurality of degrees or grade of texture, as fine, coarse, thick, or mixed.

Thus we prefer to manufacture paper make'rs' felts with, for example, an extremely heavy base fabric especially woven for needling under tension to withstand the weight, strain, and tension of substantially actual paper-making machine service, without undue distortion. When a heavy layer, such as shingle, mill, or gasket board are formed or built up on paper-machine felts, a very considerable strain is necessarily imparted to the fabric and, hence, such felts are distorted in service, as heretofore made.

By our method of needling under tension, and with a specially formed fabric, we particularly prepare the felt for such stress during use of same and thus eliminate distortion, thereby still further improving our product and insuring long life, wear-resistance, and efficient service.

We also contemplate the utilization of extremely heavy fabric with a needled layer of relatively coarse wool thereon to take the strain of the-fabric adjacent the suction boxes and rolls over which the belt is conducted, while we also needle to the opposite surface one or more layers or wool which may be, first, a coarse-layer, and then an extremely fine layer to thus give a more even, smooth, and uniform surface on which the pulp is carried. This is of still further advantage as the finer surface next to the pulp, while permitting free drainage of the same during the travel of the belt, will protect the rest of the belt against clogging as the lower and more open layers of coarser material will not be clogged or filled by any material which can escape thru the finer top surface.

A further advantage is that this finer top surface is more readily cleaned by the cleansing streams of water usually applied to the top surface of the felts once the pulp material is led free therefrom.

Thus it will be appreciated that we have devised a peculiarly beneficial structure for industrial and paper-makers felts, and we shall now describe the same in detail.

Referring to Fig. 4, a preferred form of base fabric i is illustrated wherein the warp strands 2, 2, 2 are shown running vertically in the drawings and lengthwiseof the fabric and are formed of ply yarns; whereas the filling or woof strands 3, 3, 2 are formed of cabled or twisted strands.

We have'discovered that this construction insures a minimum of stretch lengthwise of the fabric where the greatest tension is exerted and, thus, results in the least distortion of the felt during the severest service to which it is subjected. A stranded warp structure has less capacity for lengthwise stretch than the cabled structure, such as shown at 3, since the twisting of the cables givs greaterlength of material to this form of structure and, hence, greater capacity for stretch. Consequently, we prefer to form our base fabric with stranded warp and the twisted or cabled filling'layers. This fabric may be woven with large orsmall interstices, the same being somewhat overdrawn with enlarged openings in Fig. 4.

The base'fabricv I may also be of any size and diameter of warp and woof strands and, thus, of varying strength.

As shown in Figs. 5 and 6, our paper-makers felt in this form comprises a single base fabric l with the stranded warps or plies 2 lengthwise, and

' with a plurality, as herein shown three layers or upper surface, this needling operation being cffleeces, of wool 4, 5, and 6 needled to the under surface, with two layers 1 and 8 needled to the Preferably and as herein shown the lower layers which are to contact with and withstand the wear of the rollers over which the felt passes have the layers I, 5, and G of coarse, strong, wear-resisting wool while the upper layers I and 8 are of much finer wool material, thus giving a smooth top surface II to the belt on which the pulp will rest, with a relatively coarse wear-resisting surface I 2 to contact with the rollers.

In Figs. 7 and 8, we have illustrated a plurality of base fabrics, the same also being of differingsizes of warp and woof threads. In this form the lower base fabric H is of the stronger heavier type, and the second base fabric I5 is of a finer closer woven grade, with the needled layers l5, l1, and It being of relatively coarse wool and the topmost layer l9 being of fine wool to give a smooth pulp-receiving surface 2|, while the opposite' surface 2i is coarse and wear-resistant, being that contacting with the rollers. This particular structure is found to give unusual pliability and wear as well as excellent filtering qualiies.

In Fig. 3 we have illustrated a still further modification in which the two base fabric layers are of the same grade, strength, and size of material, these being indicated at 22 and 24, together with the needled layers of coarse wool 25, 26, and 21, and a top finishing layer of fine wool 28 to give a smooth pulp-receiving surface 30 on the top and a strong wear-resistant surface II on the bottogi or inside of the belt where it goes over the ro s.

These layers are individually needled to the base fabric. We needle to the base fabric 24 the fleece layer 25 on one side. and the fleece 21 on the opposite side, and thereafter apply the second base fabric 22 and needle the fleece 26 thru said base fabric 22 to the previouslyneedled layers and finally needle the layer 28 as a finish ing surface thru the fieec'e 21, as shown in Fig. 3. This sequence may be varied, if desired, but the above are found to be advantageous and feasible.

Referring to the diagrammatic showing in Fig. l, we illustrate a needling operation as applied under lengthwise tension, this diagram being shown merely for illustrative purposes.

A suitable roller is shown over which the base material herein illustrated is that of Fig. 3, with the two layers 22 and 24 of base fabric, wherein the coarse layers 25, 26, and 21 have already been needled and the fourth or finishing fine layer 28 is being applied. A forward roll 36 is held under tension in any suitable manner, as for example by straps 3'I3| attached to movable bearing blocks 38 carrying the axle for a shaft 39 on which the roller 35 runs, which is held under tension against the belt by weights 40-40 attached to each end of said straps and going over idle rolls ll4l suitably mounted on a shaft 42, as shown, or in any other suitable manner.

The needle bar indicated as in Fig. 1 and designated at 50 comprises a plurality of movable needle-carrying members adapted to move in timed relation with the feed of the belt during the needling operation, as explained and shown in said prior patents.

We have illustrated in enlarged view in Fig. 2 the needle holding bar 50 of a standard construction, as shown in said machine patents, wherein the needle with the barbs 56-56 thereon point downwardly to engage and drive the layer of wool being needled into the fabric,

After the needling operation is completed it is customary and desirable to trim, singe. or shear the surface layer, viz., layer ll of Fig. 7, also 2. of Fig. 9, or ll of Fig. 3, and thereupon the has an absorbing'or blotting eflect aiding in removing the water and moisture from the pulp as it is carried on the belt, not possible with other or prior articles.

We claim: a

As a new article of manufacture. Dmrmakers 15 felts in the form of an endless belt for use in papermaklng machinery, made by needling a plurality of fleeces to a basefabric, said fabric consisting of non-stretching ply strands forming the warp, with cable twisted strands constituting the filling, a plurality of fleeces needled to the opposite surfaces of said base material, the top surface comprising a closely needled smooth fleece for carrying pulp material, and the bottom surface comprising a fleece of coarser form permitting drainage from the pulp material therethru free of clogging, and said coarser fleece constituting a wear-resisting surface for driving over pulleys.

PATRICK H. WALSH. PEB/CIVAL 'I'. GATES. 

